Reciprocating compressor and manufacturing method

ABSTRACT

A manufacturing method for manufacturing a cylinder for a reciprocating compressor is disclosed. The method comprises the step of manufacturing a compressor barrel comprising a cylinder chamber, a first suction valve seat, fluidly coupled to the cylinder chamber through a respective first gas suction port; and a first delivery valve seat, fluidly coupled to the cylinder chamber through a respective first gas delivery port. The method further comprises the step of manufacturing a gas inlet plenum and further manufacturing a gas discharge plenum, separately from the compressor barrel.

TECHNICAL FIELD

The subject matter disclosed herein generally relates to compressors andmore specifically to reciprocating compressors. In particular,embodiments of the present disclosure concern double-actingreciprocating compressors.

BACKGROUND

Reciprocating compressors are used in several industrial fields forcompressing a gas, in particular when relatively small gas flow ratesrequire to be compressed with a high compression ratio.

Exemplary embodiments of double-acting reciprocating compressors aredisclosed in U.S. Pat. Nos. 7,418,355, 8,807,959 and in U.S. Pat. No.8,203,350. A reciprocating compressor comprises a compressor cylinderforming a cylinder chamber therein. A piston is arranged in the cylinderchamber and is driven into reciprocating motion by a prime mover, suchas an electric motor, a turbine or a reciprocating internal or externalcombustion engine, such as a Stirling engine. A crankshaft and aconnecting rod mechanism converts the rotary motion of a motor shaftinto reciprocating motion of the piston. The connecting rod is usuallydrivingly coupled to the piston through a cross-head and a piston rod.

A valve arrangement provides for gas delivery into the cylinder chamberand gas discharge from the cylinder chamber. In double-actingreciprocating compressors the piston divides the cylinder chamber into afirst compression chamber and a second compression chamber. At least onesuction valve and one delivery valve are fluidly coupled to the firstcompression chamber, and at least a further suction valve and a furtherdelivery valve are fluidly coupled to the second compression chamber.The reciprocating motion of the piston in the cylinder chamber causesgas to be sucked in one of the compression chambers through therespective suction valve, while gas is compressed in the othercompression chamber and discharged through the respective deliveryvalve, when a delivery pressure is achieved at which the delivery valveis opened.

Suction valves and delivery valves are usually automatic valves, whichautomatically open and close in response to a pressure differentialthereacross.

The suction valves are fluidly coupled to an inlet plenum, which feedsgas at a lower pressure to the cylinder chamber. The delivery valves arein turn fluidly coupled to a discharge plenum, which collects gas at ahigher pressure from the cylinder chamber.

FIG. 1 illustrates a double-acting reciprocating compressor 100 of thecurrent art. The compressor 100 comprises a compressor head 101, acompressor frame 102 and a distance piece 103, which connects thecompressor head 101 to the compressor frame 102. A crankshaft 104 isarranged in the compressor frame 102. The crankshaft 104 rotates arounda rotation axis 106. A prime mover, not shown, drives the crankshaft 104into rotation. A connecting rod 108 transmits the motion from thecrankshaft 104 to a crosshead 110, which moves reciprocatingly in acrosshead guide 112. A piston rod 114 connects the crosshead 110 to apiston 116, which is adapted to reciprocatingly slide in a chamber 118of a compressor cylinder 120. The piston 116 divides the chamber 118 ina first compression chamber and a second compression chamber. In someembodiments, the first and second compression chambers can be a head-endchamber 118A, and a crank-end chamber 118B. A process gas is selectivelysucked into each one of said head-end and crank-end chambers 118A, 118Bat a lower pressure (suction pressure), compressed and discharged at ahigher pressure (delivery pressure). Said head-end chamber 118A andcrank-end chamber 118B are provided each with at least one suction valveand one delivery valve. The suction, compression and discharge processis performed alternatively in the two chambers, i.e. when gas is suckedinto one of the head-end chamber 118A and crank-end chamber 118B, gas inthe other of said head-end chamber 118A and crank-end chamber 118B iscompressed and discharged.

Suction valves 122 of both crank-end chamber 118B and head-end chamber118A are fluidly coupled to an inlet plenum 126, which is in turnfluidly coupled to a gas source 128. Delivery valves 124 of bothcrank-end chamber 118B and head-end chamber 118A are fluidly coupled toa discharge plenum 130, which is in turn fluidly coupled to a gas output134. The inlet plenum 126 and the discharge plenum 130 are both formedin a barrel 132, which in turn forms a cylindrical side wall of thechamber 118. The gaseous flow through the inlet plenum 126 and thedischarge plenum 130 and respective suction valves and delivery valvesis complex and involves sharp bends due to the position of the valves inrespective valve seats formed in the barrel 132. Specifically, gasenters the valve seats in a direction orthogonal to the axial directionof the valves, such that the gas flow turns by 90° when flowing from theinlet plenum into the suction valves and when flowing from the deliveryvalves into the discharge plenum.

Cooling ducts 136 are further provided in the barrel 132.

The need to provide inlet plenum, discharge plenum, valve seats andcooling ducts therein, makes the barrel 132 a quite complex andexpensive piece of machinery, which must be manufactured by iron orsteel casting. Casting of complicated components is time consuming andmay frequently lead to scraps.

The shape of the inlet plenum and discharge plenum is restricted by thestructure of the barrel. Mechanical constraints result in suboptimalfluid-dynamic design of the gas inlet and discharge plenums, which inturn causes fluid-dynamic losses and reduction of the overall efficiencyof the compressor.

Also, cooling of the compressor head is inefficient and manufacturing ofthe cooling ducts is rendered complicated by the combined presence ofvalve seats, plenums and cooling arrangements in the barrel.

A need therefore exists, for improvements in the design of reciprocatingcompressors, in particular double-acting reciprocating compressors, inorder to solve or alleviate one or more of the drawbacks of thecompressors of the current art.

SUMMARY

According to one aspect, the present disclosure concerns a manufacturingmethod for manufacturing a cylinder for a reciprocating compressor. Themethod comprises a step of manufacturing a compressor barrel comprisedof a cylinder chamber, a first suction valve seat, fluidly coupled tothe cylinder chamber through a respective first gas suction port; and afirst delivery valve seat, fluidly coupled to the cylinder chamberthrough a respective first gas delivery port. The method furthercomprises the step of manufacturing a gas inlet plenum and furthermanufacturing a gas discharge plenum, separately from the compressorbarrel.

The gas inlet plenum and the gas discharge plenum can be attached aroundthe compressor barrel in fluid communication with the gas suction portand the gas delivery port. The gas inlet plenum and the gas dischargeplenum can thus be designed according to optimization criteria, tominimize the gas pressure losses along the gas path, without beingsubjected to mechanical constraints imposed by the shape of thecompressor barrel.

According to a further aspect, a manufacturing method for manufacturinga cylinder for a reciprocating compressor is described herein, whichcomprises the following steps:

mounting a first suction valve in a first suction valve seat provided ina compressor barrel and fluidly coupled through a first gas suction portto a cylinder chamber arranged in the compressor barrel;

mounting a first delivery valve in a first delivery valve seat providedin the compressor barrel and fluidly coupled to the cylinder chamberthrough a first gas delivery port;

mounting a gas inlet plenum on the compressor barrel and in fluidcommunication with first suction valve seat;

mounting a gas discharge plenum on the compressor barrel and in fluidcommunication with the first delivery valve.

According to a yet further aspect, a reciprocating compressor isdisclosed, comprising a compressor barrel with a cylinder chambertherein and a piston, adapted for reciprocatingly sliding in thecylinder chamber. The compressor further comprises a first suction valvefluidly coupled to the cylinder chamber and a first delivery valvefluidly coupled to the cylinder chamber. Furthermore, the compressorcomprises a gas inlet plenum fluidly coupled to the first suction valveand a gas discharge plenum fluidly coupled to the first delivery valve.The gas inlet plenum and the gas discharge plenum are mechanicallyconnected to the compressor barrel and external thereto.

Features and embodiments are disclosed here below and are further setforth in the appended claims, which form an integral part of the presentdescription. The above brief description sets forth features of thevarious embodiments of the present invention in order that the detaileddescription that follows may be better understood and in order that thepresent contributions to the art may be better appreciated. There are,of course, other features of the invention that will be describedhereinafter and which will be set forth in the appended claims. In thisrespect, before explaining several embodiments of the invention indetails, it is understood that the various embodiments of the inventionare not limited in their application to the details of the constructionand to the arrangements of the components set forth in the followingdescription or illustrated in the drawings. The invention is capable ofother embodiments and of being practiced and carried out in variousways. Also, it is to be understood that the phraseology and terminologyemployed herein are for the purpose of description and should not beregarded as limiting.

As such, those skilled in the art will appreciate that the conception,upon which the disclosure is based, may readily be utilized as a basisfor designing other structures, methods, and/or systems for carrying outthe several purposes of the present invention. It is important,therefore, that the claims be regarded as including such equivalentconstructions insofar as they do not depart from the spirit and scope ofthe present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the disclosed embodiments of theinvention and many of the attendant advantages thereof will be readilyobtained as the same becomes better understood by reference to thefollowing detailed description when considered in connection with theaccompanying drawings, wherein:

FIG. 1 illustrates a sectional view of a double-effect reciprocatingcompressor of the current art;

FIG. 2 illustrates a sectional view of a double-effect reciprocatingcompressor according to an embodiment according to the presentdisclosure;

FIG. 3 illustrates a sectional view taken along the line of FIG. 2;

FIG. 4 illustrates a flowchart summarizing manufacturing methodsaccording to the present disclosure.

DETAILED DESCRIPTION

The following detailed description of the exemplary embodiments refersto the accompanying drawings. The same reference numbers in differentdrawings identify the same or similar elements. Additionally, thedrawings are not necessarily drawn to scale. Also, the followingdetailed description does not limit the invention. Instead, the scope ofthe invention is defined by the appended claims.

Reference throughout the specification to “one embodiment” or “anembodiment” or “some embodiments” means that the particular feature,structure or characteristic described in connection with an embodimentis included in at least one embodiment of the subject matter disclosed.Thus, the appearance of the phrase “in one embodiment” or “in anembodiment” or “in some embodiments” in various places throughout thespecification is not necessarily referring to the same embodiment(s).Further, the particular features, structures or characteristics may becombined in any suitable manner in one or more embodiments.

The exemplary reciprocating compressors disclosed herein alleviate orsolve the drawbacks and limitations of the prior art by separating thegas inlet plenum and gas discharge plenum from the compressor barrel.The design of both the gas inlet plenum and the gas discharge plenum canthus be optimized from a fluid-dynamic perspective, since lessmechanical constraints are present. The shape of the inlet plenum anddischarge plenum do not have to conform to the shape of the barrel, thecooling ducts and valve seats housed therein. The orientation of theinlet plenum and discharge plenum with respect to the position of thesuction valves and delivery valves can be optimized. More space isavailable in the wall of the barrel to accommodate the valve seats andthe cooling ducts. Also the shape of the cooling ducts can beameliorated from the point of view of heat exchange efficiency, as wellas from the point of view of machining.

The barrel can be more easily manufactured and less expensive productiontechniques, rather than iron or steel casting, can be used. Forinstance, the barrel can be manufactured by forging or centrifugalcasting, which makes the overall manufacturing process quicker, lessexpensive and less prone to generate scraps.

The inlet plenum and discharge plenum can be produced usingmanufacturing processes, which allow complex shapes to be achieved, e.g.by additive manufacturing. Optimal design can thus be achieved, whichresult in reduction of fluid-dynamic losses in the inlet and dischargegas flows.

While the compressor structure and the manufacturing processes disclosedherein can be beneficial also for the production of single-actingreciprocating compressors, they are particularly beneficial for theproduction of double-acting reciprocating compressors, where the shapeof the gas inlet plenum and gas discharge plenum is particularly complexdue to the higher number of suction valves and delivery valves providedin the compressor head.

A double-acting reciprocating compressor comprises a cylinder comprisedof a compressor barrel and a cylinder chamber formed in the barrel. Thecylinder chamber is divided in a so-called head-end chamber and aso-called crank-end chamber by a piston, arranged for reciprocatinglysliding therein. The head-end chamber is fluidly coupled to a firstsuction valve through a first gas suction port and to a first deliveryvalve through a first gas delivery port. The crank-end chamber isfluidly coupled to a second suction valve through a second gas suctionport and to a second delivery valve through a second gas delivery port.

Thus, the double-acting reciprocating compressor is adapted to suck gasin one of the crank-end chamber and head-end chamber through therespective suction valve, while gas is compressed in the other of thecrank-end chamber and head-end chamber and finally delivered through therespective delivery valve.

Each crank-end chamber and head-end chamber can be fluidly coupled tomore than one suction valve and one delivery valve. For instance, tworespective suction valves and two respective delivery valves can befluidly coupled to each one of said head-end chamber and crank-endchamber, to maximize gas flow and minimize head losses.

The larger the number of suction valves and delivery valves, the morebeneficial the use of gas inlet plenum and gas discharge plenummanufactured separately from the compressor barrel, as this gives morefreedom in shaping the gas ducts in the gas inlet and discharge plenums,and imposes less space and mechanical constraints.

All suction valves can be fluidly coupled to a single gas inlet plenum.All delivery valves can be fluidly coupled to a single gas dischargeplenum.

The suction valves and the delivery valves can be automatic valves,which open and close responsive to a pressure difference thereacross.

The piston can be connected to a rotary crankshaft trough a connectingrod. Large reciprocating compressors, especially double-actingreciprocating compressors as disclosed herein are further provided witha piston rod and a crosshead. The piston, the piston rod and thecross-head are controlled according to a reciprocating rectilinearmotion imparted to the crosshead by the rotary crankshaft and theconnecting rod.

FIG. 2 illustrates a schematic sectional view of a cylinder and relevantcomponents of a double-acting reciprocating compressor 1 according tothe present disclosure in one embodiment. The section is taken along theaxis of the reciprocating compressor cylinder.

According to embodiments disclosed herein, the compressor 1 can comprisea compressor head 3, a compressor frame 5 and a distance piece 7, whichconnects the compressor head 3 to the compressor frame 5. The compressorhead 3 contains the compression chamber, as will be described below.

A crankshaft 9 is arranged in the compressor frame 5 for rotation arounda shaft axis 9A. A prime mover, not shown, drives the crankshaft 9 intorotation around the axis 9A. The prime mover can be a reciprocatinginternal combustion engine, such as a Diesel engine. In otherembodiments, the prime mover can be a reciprocating external combustionengine, such as a Stirling engine. The reciprocating compressor 1 canalso be driven by a gas turbine engine, by a steam turbine, or by anelectric motor, for instance.

A connecting rod 11 connects the crankshaft 9 to a crosshead 13. Thecrosshead 13 is guided along cross-head guides 15 housed in the frame 5.The rotation motion of the crankshaft 9 (arrow f9) is thus convertedinto a reciprocating motion of the crosshead 13 (arrow f13). A pistonrod 17 connects the crosshead 13 to a piston 19, which is adapted toreciprocatingly slide in a chamber 21 of a compressor barrel 18. Thepiston 19 divides the chamber 21 in two compression chambers, namely ahead-end chamber 21A, and a crank-end chamber 21B.

One or more respective suction valves are provided to fluidly connectthe head-end chamber 21A and the crank-end chamber 21B selectively witha gas inlet plenum 20. One or more respective delivery valves arefurther provided to fluidly connect the head-end chamber 21A and thecrank-end chamber 21B selectively with a gas discharge plenum 22.

The gas inlet plenum 20 is fluidly coupled to a low-pressure gas source31, and the gas discharge plenum 22 is fluidly coupled to ahigh-pressure gas source 33.

In the sectional view of FIG. 2 a single gas suction valve for eachchamber 21A, 21B and a single gas delivery valve for each chamber 21A,21B are visible. A plurality of such gas suction valves and gas deliveryvalves can be provided for each one of said head-end chamber 21A andcrank-end chamber 21B. Specifically in the sectional view of FIG. 2 afirst gas suction valve 23A is shown for fluidly connecting the head-endchamber 21A with the gas inlet plenum 22 and a second gas suction valve23B is shown for fluidly connecting the crank-end chamber 21B to the gasinlet plenum 22. Similarly, a first gas delivery valve 25A is providedfor fluidly connecting the head-end chamber 21A with the gas dischargeplenum 25 and a second gas delivery valve 23B is shown for fluidlyconnecting the crank-end chamber 21B to the gas discharge plenum 22.

In the cross-sectional view of FIG. 3 a total of four gas valves, namelytwo gas suction valves and two gas delivery valves, are shown in fluidcommunication with the head-end side chamber 21A. A similar arrangementis provided for the crank-end chamber 21B.

In other embodiments, not shown, a different number of valves can beprovided for each chamber.

The gas suction valves 23A, 23B and the gas delivery valves 25A, 25B canbe automatic valves, i.e. valves which automatically open and close inresponse to a pressure differential thereacross.

As known, the reciprocating motion of the piston 19 according to doublearrow f19 causes gas to be sucked through gas suction valves 23A, 23Bfrom the gas inlet plenum 20 in the head-end chamber 21A and in thecrank-end chamber 21B, selectively. Simultaneously, gas is compressed isselectively compressed in the crank-end chamber 21B and in the head-endchamber 21A and discharged through the gas delivery valves 25B, 25A inthe discharge plenum 22.

The gas suction valves 23A, 23B and the gas delivery valves 25A, 25B canbe housed in respective valve seats schematically shown at 27A, 27B forthe gas suction valves 23A, 23B and at 29A, 29B for the gas deliveryvalves 25A, 25B, see also FIG. 3. The valve seats 27A, 27B are in fluidcommunication with the respective head-end chamber 21A and crank-endchamber 21B through respective gas suction ports 30 (FIG. 3). The valveseats 29A, 29B are in fluid communication with the respective head-endchamber 21A and crank-end chamber 21B through respective gas deliveryports 32 (FIG. 3).

The valve seats 27A, 27B and 29A, 29B are arranged in the compressorbarrel 18, develop along the thickness thereof and have respective gasinlet apertures 34 and gas outlet apertures 36 on the outer surface ofcompressor barrel 18.

The gas inlet plenum 20 and the gas discharge plenum 22 are mounted onthe outer surface of the compressor barrel 18. The gas inlet plenum 20can be provided with a total number of gas ports 20A equal to the totalnumber of suction valves 23A, 23B of the compressor head 3. The gasdischarge plenum 22 can in turn be comprised of a total number of gasports 22A equal to the total number of delivery valves 25B of thecompressor head 3.

The arrangement of the gas ports and apertures of the gas dischargeplenum 22, the gas inlet plenum 20 and the valve seats 27A, 27B, 29A,29B is such that gas flows in a substantially axial direction from thegas outlet 20A of the gas inlet plenum 20 towards and through the valveseats 27A, 27B and the respective gas suction valves 23A, 23B. Moreover,the gas flows in a substantially axial direction through the gasdelivery valves 25A, 25B, the valve seats 29A, 29B towards the gas ports22A of the gas discharge plenum 22.

The term “axial direction” as used herein can be understood as adirection substantially parallel to an axial extension of the gassuction valves 23A, 23B and gas delivery valves 25A, 25B, along whichthe gas flows through the respective valves.

By arranging the gas inlet plenum 20 and the gas discharge plenum 22outside the barrel 18, the gas flow is optimized, since no sharp 90°bent is required for the gas upon entering the valve seats. The gasinlet plenum 20 and the gas discharge plenum 22 can be designed with ahigher degree of freedom, as they do not require to be housed in thereduced space available within the thickness of the compressor barrel,as in the reciprocating compressors of the current art. The shape of theinner gas passages in the gas inlet plenum 20 and gas discharge plenum22 can be optimized for reduced pressure losses.

In addition, manufacturing of the barrel 18 is made simpler. As a matterof fact, the barrel 18 can have a simple cylindrical shape, and can beobtained by forging or centrifugal casting. The valve seats 27A, 27B and29A, 29B can be produced by simple machining through the cylindricalwall of the semi-finished barrel 18.

Additionally, cooling ducts 38 (FIG. 3) can be provided in thesemi-finished barrel 18. In some embodiments, the cooling ducts 38extend parallel to the barrel axis, i.e. parallel to the direction ofthe reciprocating motion of the piston 19 in the chamber 21, as shown inFIG. 3. Machining of the cooling ducts 38 is simple and inexpensive, ifcompared to the manufacturing of complex cooling ducts in the barrels ofthe current art.

In other embodiments, the valve seats 27A, 27B, 29A, 29B and/or thecooling ducts 38 can be produced during casting.

According to some embodiments, the cooling ducts and/or the valve seatsare produced by chip-removal machining.

The gas inlet plenum, or the gas discharge plenum or both can bemanufactured by additive manufacturing. This manufacturing techniqueallows the production of components having a complex shape at low cost.The shape of the gas flow paths inside the gas inlet plenum and the gasdischarge plenum can be designed such as to achieve optimum flowconditions and minimize losses. Additive manufacturing allows productionof flow ducts of substantially any shape, no matter how complex theyare. The additive manufacturing process can be selected from the groupcomprising: Selective Laser Sintering (SLS), Powder bed fusion (PBF),Selective Laser Melting (SLM), Direct Metal Laser Sintering (DMLS),Electron Beam Melting (EBM), Multi Jet Fusion (MJF).

Both the gas inlet plenum and the gas discharge plenum can bemanufactured as a single, monolithic piece of machinery, without theneed for connecting to one another two or more elements, e.g. bysoldering, welding, screwing or the like. The resulting single-piecemonolithic plenum meets higher quality standards. Production of scrapsor defective components is prevented or limited. The manufacturingprocess is faster and requires less manufacturing skill.

The gas inlet plenum 20 and the gas discharge plenum 22 can be mountedaround the compressor barrel 18 and coupled thereto by any suitablemeans. For instance, connecting flanges can be provided around eachinlet aperture 34 and each outlet aperture 36. The flanges can beconnected to the compressor barrel 18 e.g. by means of screws, such thatthe gas inlet plenum and the gas discharge plenum can be easilydisassembled from the compressor barrel 18, e.g. in order to repair orreplace the suction valves and delivery valves, as required.

In less advantageous embodiments, the gas inlet plenum and the gasdischarge plenum can be manufactured by assembling to one another pipesections, which can in turn be made by any manufacturing processsuitable for pipe manufacturing.

While the disclosed embodiments of the subject matter described hereinhave been shown in the drawings and fully described above withparticularity and detail in connection with several exemplaryembodiments, it will be apparent to those of ordinary skill in the artthat many modifications, changes, and omissions are possible withoutmaterially departing from the novel teachings, the principles andconcepts set forth herein, and advantages of the subject matter recitedin the appended claims. Hence, the proper scope of the disclosedinnovations should be determined only by the broadest interpretation ofthe appended claims so as to encompass all such modifications, changes,and omissions. In addition, the order or sequence of any process ormethod steps may be varied or re-sequenced according to alternativeembodiments.

What we claim is:
 1. A manufacturing method for manufacturing a cylinderfor a reciprocating compressor; said method comprising the followingsteps: manufacturing a compressor barrel comprising a cylinder chamber,a first suction valve seat, fluidly coupled to the cylinder chamberthrough a respective first gas suction port; and a first delivery valveseat, fluidly coupled to the cylinder chamber through a respective firstgas delivery port; manufacturing a gas inlet plenum and furthermanufacturing a gas discharge plenum, separately from the compressorbarrel.
 2. The manufacturing method of claim 1, further comprising thesteps of: mounting a first suction valve in said first suction valveseat; mounting a first delivery valve in said first delivery valve seat;and mounting the gas inlet plenum and the gas discharge plenum on thecompressor barrel and in fluid communication with the first suctionvalve seat and the first delivery valve seat, respectively.
 3. Themanufacturing method of claim 1, wherein the step of manufacturing thegas inlet plenum comprises the step of manufacturing the gas inletplenum by additive manufacturing.
 4. The manufacturing method of claim1, wherein the step of manufacturing the gas discharge plenum comprisesthe step of manufacturing the gas discharge plenum by additivemanufacturing.
 5. The manufacturing method of claim 1, wherein thecompressor barrel comprises: a second suction valve seat, fluidlycoupled to the cylinder chamber through a second gas suction port, and asecond delivery valve seat, fluidly coupled to the cylinder chamberthrough a respective second gas delivery port; wherein the gas inletplenum is configured to provide fluid communication with the firstsuction valve seat and the second suction valve seat; wherein the gasdischarge plenum is configured to provide fluid communication with thefirst delivery valve seat and the second delivery valve seat; whereinthe first suction valve seat and the first delivery valve seat arearranged proximate to a head end of the cylinder chamber; and whereinthe second suction valve seat and the second delivery valve seat arearranged proximate to a crank shaft end of the cylinder chamber.
 6. Themethod of claim 5, further comprising the steps of: mounting arespective suction valve in the first suction valve seat and in thesecond suction valve seat; mounting a respective delivery valve in thefirst delivery valve seat and in the second delivery valve seat;mounting the gas inlet plenum on the compressor barrel and in fluidcommunication with the first suction valve seat and the second suctionvalve seat; mounting the gas discharge plenum on the compressor barreland in fluid communication with the first delivery valve seat, andsecond delivery valve seat.
 7. The method of claim 1, wherein thecompressor barrel is provided with cooling ducts extending substantiallyparallel to an axial extension of said compressor barrel.
 8. Amanufacturing method for manufacturing a cylinder for a reciprocatingcompressor; said method comprising the following steps: mounting a firstsuction valve in a first suction valve seat provided in a compressorbarrel and fluidly coupled through a first gas suction port to acylinder chamber arranged in the compressor barrel; mounting a firstdelivery valve in a first delivery valve seat provided in the compressorbarrel and fluidly coupled to the cylinder chamber through a first gasdelivery port; mounting a gas inlet plenum on the compressor barrel andin fluid communication with the first suction valve seat; mounting a gasdischarge plenum on the compressor barrel and in fluid communicationwith the first delivery valve seat.
 9. The method of claim 8, furthercomprising the following steps: mounting a second suction valve in asecond suction valve seat provided in the compressor barrel and fluidlycoupled through a second gas suction port to the cylinder chamber;mounting a second delivery valve in a second delivery valve seatprovided in the compressor barrel and fluidly coupled to the cylinderchamber through a second gas delivery port; mounting the gas inletplenum in fluid communication with second suction valve seat, andmounting the gas discharge plenum in fluid communication with the seconddelivery valve seat; wherein a piston is arranged in the cylinderchamber, the piston dividing the cylinder chamber in a head-end chamberand a crank-end chamber, respectively; and wherein the first suctionvalve and the first delivery valve are in fluid communication with thehead-end chamber, and the second suction valve and the second deliveryvalve are in fluid communication with the crank-end chamber.
 10. Areciprocating compressor comprising: a compressor barrel with a cylinderchamber therein; a piston, adapted for reciprocatingly sliding in thecylinder chamber; a first suction valve fluidly coupled to the cylinderchamber; a first delivery valve fluidly coupled to the cylinder chamber;a gas inlet plenum fluidly coupled to the first suction valve; a gasdischarge plenum fluidly coupled to the first delivery valve; whereinthe gas inlet plenum and the gas discharge plenum are mechanicallyconnected to the compressor barrel and external thereto.
 11. Thereciprocating compressor of claim 10, wherein at least one, andpreferably both of the gas inlet plenum and the gas discharge plenum areformed by additive manufacturing.
 12. The reciprocating compressor ofclaim 10, wherein the first suction valve is arranged in a first suctionvalve seat provided in the compressor barrel and in fluid communicationwith the cylinder chamber through a first gas suction port; and whereinthe first delivery valve is arranged in a first delivery valve seatprovided in the compressor barrel and in fluid communication with thecylinder chamber through a first gas delivery port.
 13. Thereciprocating compressor of claim 10, wherein: the piston divides thecylinder chamber in a head-end chamber and a crank-end chamber; thefirst suction valve and the first delivery valve are fluidly coupled tothe head-end chamber; a second suction valve and a second delivery valveare fluidly coupled to the crank-end chamber; the gas inlet plenum isfluidly coupled to the first suction valve and to the second suctionvalve; and the gas discharge plenum is fluidly coupled to the firstdelivery valve and to the second delivery valve.
 14. The reciprocatingcompressor of claim 13, wherein the second suction valve is arranged ina second suction valve seat provided in the compressor barrel and influid communication with the cylinder chamber through a second gassuction port; and wherein the second delivery valve is arranged in asecond delivery valve seat provided in the compressor barrel and influid communication with the cylinder chamber through a second gasdelivery port.
 15. The reciprocating compressor of claim 10, wherein thecompressor barrel comprises a plurality of cooling ducts, extending in alongitudinal direction substantially parallel to the direction ofmovement of the piston in the cylinder chamber.